In integrated circuit technology, the Schottky diode has many important advantages over the regular diode such as low forward voltage drop, being majority carrier device, fast switching and so on. Meanwhile, it is required to enhance or to improve some performances of the Schottky diode, for example, a higher forward current, a lower leakage current, a higher breakdown voltage, etc.
Sometimes improving one parameter needs to compromise another parameter. For an instance, a low leakage Schottky diode comes with a limited forward current capability. FIG. 1 schematically depicts a cross-section structure of a typical Schottky diode 100. Conventionally, a P-type guard ring structure 108 is comprised in diode 100 configured to improve at least the performances of breakdown voltage and leakage current. However, P-type guard ring 108 also brings some parasitic effects. For example, when a large forward current flows through Schottky diode 100, a serious minority injection and a PNP transistor action may occur, and this may lead to either undesirable parametric deficiency or destructive failure. Hence the forward current ability of low leakage Schottky diode is limited.